Push-rod for engines.



J. W. NILSON.

PUSH ROD FOR ENGINES.

APPLICATION FILED MAR. 16. 1914.

1 ,1 1 AM. Patented Nov. 23, 1915.

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JOEL W. NILSON, 0F DETROIT, MICHIGAN.

PUSH-BOD FOR ENGINES.

Specification of Letters Patent.

Application filed March 16, 1914. Serial No. 824,915.

' cation.

My invention relates to an improved push rod for operating valves ofinternal combustion engines.

In internal combustion engines the valves are generally operatedmechanically by means of push rods interposed between the cams of thecam shaft and the valve stems, and as the parts become worn it is foundnecessary to adjust the length of the push rod so as to properly actuatethe valves. This has enerally been provided for by threading into theupper end of the body portion of the push rod a common screw bolt, whichoftentimes becomes loosened and causes unintentional opening of thevalves and consequently improper operation of the engine.

It is one of the objects of my invention to provide the proper length tothe push rod by embodying therein a self-locking screw bolt, which whenonce positioned will remain so until it is found necessary to makeadjustment due to wearing of parts.

It further has for its object the provision of a. divided screw boltprovided with means for retaining the threads of the parts of said screwbolt out of continuous trend, said means yielding to pressure toenablethe threads of the two parts of the bolt to be brought intoperfect alinement for threading the bolt into the body of the push rod.-

VVith these and other objects in view, the invention consists in thenovel features of construction and in the arrangement and combination ofparts to be hereinafter described and particularly pointed out in thesubjoined claims.

In the drawings,Figure 1 is a side elevation of an internal combustionengine partly broken away to show the operative arrangement of myimproved push rod relative to the valves of the engine. Fig. 2 is anenlarged vertical section taken on line 22, Fig. 1. Fig. 3 is asectional elevation showing. the screw bolt in elevation and the upperend of the body of the push rod into which it IS threaded, in section;the upper part of the screw bolt being shown out of threaded engagementwith the body of the push rod. Fig. 4 is a similar view showing thescrew bolt in its position of use. Fi 5 1s a section taken on line 5-5,Fig. 3. ig. 6 1s a cross section taken on line 66, Flg. 4.

Like numerals of reference refer to like parts throughout the severalfigures.

The reference numeral 10 designates a gasolene engine having the usualvalve chest 11 in which the valves 12 are operatively held, said valvesbeing closed by the usual springs 13 which surround the stems 14extending from said valve chest. 15 designates the engine cam shaft hav-1ng the usual cams 16 thereon which are adapted to actuate the push rods17 which are slidable in suitable guides 18 formed on the engine casing,or otherwise arranged.

My improved push rod comprises a body portion 19 having an axial bore 20threaded at its upper portion and in this threaded upper portion myimproved screw bolt 21 is adapted to be inserted to any adjustedposition. Said screw bolt is self-locking within the body portion 19 andcomprises two divided parts 22, 23, the upper part 22, which may betermed the main part, being externally threaded, as at 24, and having atits upper end a hexagonal or other head 25 permitting the use of awrench or other tool for adjusting the bolt. At its lower end said upperor main part has formed thereon a flattened central portion or tenon 26,from the lower end of which extends a pin or stem 97, said flattenedportion or tenon having its side edges 28 madeconvex to conform to thethreaded portion of said upper part, and these convex edges are threadedto match the pitch of the threads of said threaded portion. I

The part 23, which may be termed the lower or looking part, is providedwith a cross groove or mortise 29 in which the flat central portion ortenon of the main part is adapted to fit. Said part 23 is also providedwith an axial opening 30 extending from said cross groove or mortisetothe lower face, through which the pin or stem 27 is passed. Surroundingsaid pin or stem Patented Nov. 23, 1915. p

is a spiral spring 31 which bears at its upper end against the undersideof lower or locking part 23 and at its lower end against a washer 32which is held to said pin or stem by upsetting the end of the latter, asat. 33. This spring presses the lower or locking part 23 upwardly withthe bottom of the cross groove or mortise of said lower or locking partin, contact with the lower end of the central flattened portion or tenorof the upper or main part, and when in this position the threads of thelower or looking part are out of alinement with the threads at theconcaved edges of saidflattened portion or tenon.

When inserting the locking screw bolt into the body of the push rod, thethreads on the lower or looking part of the screw bolt will enterwithout ofi'ering any resistance, but when the bolt is threaded intosaid body sufliciently to bring the threaded flattened portion or tenonofthe upper or main part in position for entrance into the body of thepush rod, it will be necessary to draw upwardly on said upper or mainpart to slightly raise the same against the action of the spring 31,which brings the threads on the concaved edges of said flattened portionor tenon in alinement with the threads on said lower or locking part,thus permitting the screw bolt to be threaded into the body of the pushrod to the desired extent. The'spring 31, however, offers considerableresistance to the insertion of the upper or main part of the screw boltinto the body of the push rod, which resistance tends to crowd the upperbevel faces of the threads of said lower or looking part against thelower faces of the threads in the body portion of the push rod, thusretaining the screw bolt in any adjusted position, due to the fact thatthe resistance is sufficient to prevent unscrewing of the bolt, exceptby a turning action of the same.

While my invention is particularly designed for push rods of internalcombustion engines, it may nevertheless be adapted for use for variouspurposes where screw bolts are employed for fastening one part toanother, and changes in details of construction may also be resorted towithout departing from my invention or sacrificing any of the advantagesthereof.

Having thus described my invention, what I claim is,

1. A push rod for engines, comprising a body portion having an axialthreaded bore and a screw bolt threaded into said body portioncomprising two co-axial parts provided with means to cause it to lockitself into said body portion.

2.- A push rod for engines, comprising a body portion having an axialthreaded bore extending inwardly from its upper end, and a screw boltthreaded into said bore and comprising two co-axial externally-threadedparts, the threads of one part being normally out of alinement withthose of the other, and yielding means to permit movement of one of saidparts to bring the threads of both parts into alinement.

3. A push rod for engines, comprising a body portion having an axialthreaded bore and a screw bolt adjustably threaded within said bore andcomprising an externallythreaded main part and a similarly threadedco-axial secondary part, said parts having their threads normally out ofalinement and having means to prevent rotation of one independent of theother, and means yieldable to force, in the direction of the axis ofsaid screw bolt, so as to permit one part to move on the other and bringthe threads of both parts into alinement.

4. A push rod for engines, comprising a body portion having an axialthreaded bore and a divided bolt having co-axial parts threaded intosaid bore, and means for applying force to one part of said bolt so asto cause the threads thereof to bind against the threads of said bore.

5. A push rod for engines, comprising a body portion having an axialthreaded bore, a screw bolt threaded into said bore and comprising amain part provided with an axial stem, and a secondary part throughwhich said stem is passed, said main and secondary parts beingexternally threaded and having co-acting means to compel one to turnwith the other, the threads of the secondary part being normally out ofaline ment with the threads of the main part,

and a spring surrounding said stem and bearing against the lower orinner end of said secondary part and being adapted to yield when movingthe main and secondary parts relatively.

6. A push rod for engines, comprising a body portion having a threadedbore and a screw bolt threaded into said bore and comprising a main parthaving a head at one end and a tenon at its other end, said main parthaving also an axial stem extending from said tenon, a secondary parthaving a mortise to receive said tenon and an axial opening throughwhich said stem is passed, a spring surrounding said stem and bearingagainst the lower or inner end of said secondary part, and means at thefree end of said stem to retain said spring thereon.

7. A screw bolt comprising a main externally-threaded part having a headat its upper end, a flattened portion at its lower end and a stemextending from the lower edge of said flattened portion, anexternallythreaded secondary part having a cross groove to receive saidflattened portion and an axial opening through which said stem ispassed, and a spiral spring surrounding said stem and held thereon tobear against memoe the lower end of said secondary part,-the

threads of said secondary. and mam par being held normally out ofalinement by said spring andsaid spring being adapted. 5 to yield underforce to permit of bringing the threads of said main and secondary partsinto alinement.

v Iii testimony wheredf I amy signature ts in presence of two witnesses1 JOEL W. NELSON.

Witnesses: EMIL NEUHART,

EDA M. SCHWEIGER.

